This is a Taoist text of internal alchemy with meditation instruction, and some lineages that teach material of this kind pass it only from a teacher to a prepared student; this edition's own pages do not say which applies here.
What would resolve this Someone familiar with this translation and its source lineage confirming whether the meditation instruction it contains is still treated as limited to guided students or is offered here as published material.
OpenTrans. Richard Wilhelm; commentary by Carl Jung; English trans. Cary F. Baynes, The Secret of the Golden Flower: A Chinese Book of Life